The viewer below is a rare folding Sawyers
View-Master Compact Viewer, dating to around 1960 and made from plastic.

The viewer folds totally flat when not in use. The
hinges are actually made of tape and the internal supporting stay is held
taught by an elastic band. Viewing reels with this viewer is a delight as
they appear bright and clear. The reels are advanced manually.

These viewers are so rare that when they do become
available they can fetch prices well above what would be expected for such
a simple device.

On the reverse side of these
instructions is an advert for Model E, F and D viewers, enabling the
folding viewer to be dated between 1959 and 1961, as 1959 is the date when
the Model F went in to production and 1961 is the date the Model E went
out of production.